Popular Science Monthly/Volume 60/March 1902/Science in 1901
|SCIENCE IN 1901.|
IN a review of the scientific work of 1901, astronomy, as the oldest of the sciences, may fitly claim first mention, especially as it fell to the astronomers to make what was, on the whole, the most exciting discovery of the year. This was a new and brilliant star in Perseus, which appeared to spring into existence in a remarkably sudden manner. That portion of the heavens in which it was situated was photographed at Harvard on February 19, and no sign of it was to be detected on the plates when they were developed; yet only a day or two afterwards it was seen by Dr. T. D. Anderson, of Edinburgh, and by other observers as a star of between the second and third magnitude. The suddenness of its appearance was equalled by the rapidity with which its size varied, and this inconstancy, together with the extraordinary changes that took place in the character of its spectrum, provided astronomers with a theme for speculation, the resources of which are yet very far from being exhausted. In April a new comet, said to be the brightest since that of 1883, was discovered in the southern hemisphere by several observers. In May its tail, which at first was 10° in length and curved slightly to the south, split into three parts. On May 18th, there was an eclipse of the sun, the line of totality passing across the Indian Ocean through Sumatra, Borneo and New Guinea. The party from Greenwich selected their station in Mauritius, where the duration of totality was only three and a half minutes, and enjoyed the advantage of good weather. Other observers who took up their positions in Sumatra had a longer (six minutes') duration of totality, but were not quite so fortunate as regards weather.
In pure physics, perhaps the most interesting single achievement of the year was the experimental proof that light, as predicted by Maxwell and by Bartoli, exerts a mechanical pressure. Many observers have already attempted to detect this phenomenon, among them being Sir William Crookes, who at first thought he had succeeded in so doing with his radiometer, until it was found that his effect was many thousand times too great. Curiously enough, success was announced almost simultaneously in two different quarters, by Professor Lebedew, of Moscow University, in Europe, and by Messrs. Nicholls and Hull in America. The work of the latter observers appears to be the less precise of the two, for they do not claim that it does more than prove the existence of a pressure, not due to gas-molecules, of the nature and order of magnitude required. Professor Lebedew's measurements are, however, in close agreement with the amounts as calculated from the theory; he finds that the pressure per square meter is 0.4 milligram for absolutely black bodies, and double as much for perfect reflectors. This experimental verification of one consequence of Maxwell's wonderful electro-magnetic theory suggests reference to another which is gradually passing out of the experimental stage and becoming of practical utility. It is only a few years since Principal Lodge astonished the British Association by showing that the electric waves in connection with which Hertz's name is famous, could be propagated to a distance of half a mile or so; yet already the wireless telegraphy so initiated has become a recognized portion of the equipment of ships in all the important navies of the world. In the mercantile marine, too, it is making way, so much so that Lloyd's, in the course of the 5'ear, contracted to have it fitted in a number of their signal stations round the British coasts. Almost every country can show workers who are engaged, with more or less success, in perfecting its appliances, among them being Popoff in Russia, Slaby in Germany, Guarini in Belgium, Ducretet in France, and Marconi in England. The last-named, by using waves a thousand feet long, succeeded in detecting electro-magnetic radiation which had traveled, 1,800 miles from the source that produced it, and he is looking forward to the early establishment of a commercial system of sending messages across the Atlantic by wireless telegraphy, and later to opening up communication with the Cape. But while the performance of such feats in long-distance transmission is certainly a legitimate object of ambition, it must not be forgotten that very much remains to be done in perfecting wireless telegraphy for comparatively short distances. If ever it is to become of real commercial importance, means must be found not only to enable two parties to communicate with each other without fear of their message being overheard, but also to prevent a third party from making communication impossible altogether by the simple device of working his own apparatus and thus rendering the signals unintelligible. Even before these refinements comes the necessity of ensuring certain transmission of simple signals over moderate distances. The imperfections of present methods are sufficiently illustrated by the experiences of the Ophir and her consorts, and by the difficulty which the Admiralty have found in obtaining coherers that can be trusted to respond satisfactorily over their test-distance of 70 miles—a difficulty which has induced them to take the manufacture of these delicate pieces of apparatus virtually into their own hands.
Of all the physical forces which it is the business of science to investigate, none bulked more largely in the public eye than electricity. The idea of distributing current for various purposes from a central station to a large surrounding area made distinct progress during the year. though in Mond gas Parliament sanctioned a novel and rival method of power transmission. While its use for lighting, for electrolytic manufactures, etc., steadily advanced, it was in regard to its applications to traction that electricity was most conspicuous. Some schemes of this sort were brought into actual operation, some were definitely decided upon; but more still were mere suggestions, few of which have much chance of being translated into fact. Among the last class must be ranked the host of tube-railways which threaten to invade London. If Parliament were to sanction all those proposed and if (what is not less unlikely) their promoters were to obtain the money for their construction, it seems that in some places the subsoil of the City of London would be transformed into a solid mass of iron tubes, and it is doubtful whether there would even be room for all in the earth, whatever the ingenuity of drawing-offices may do in plans. This activity on the part of promoters is largely a result of the success of the Central London Railway, but it is conveniently forgotten that there are other tube railways which cannot point to anything like similar results. In the near future, too, it does not seem improbable that there may be a change in popular sentiment in favor of shallow lines just below the surface, where efficient ventilation will be obtainable; for people are discovering that steam and sulphur are not the only things that make an atmosphere offensive, and they may soon realize that to roll a mass of used-up air forwards and backwards in a narrow tunnel, without ever renewing it, does not constitute ventilation sufficient either for comfort or for health. During the year many towns brought electric traction into operation on their surface tramlines, and after protracted obstruction the authorities of Kew Observatory, who feared that certain magnetic observations carried on at that somewhat unsuitable site would be injuriously affected by stray electric currents, agreed to withdraw their opposition to the opening of the first electric tramway seen in London, in consideration of the company which owns the lines contributing £10,000 towards the expenses of moving the instruments. Among proposals which were definitely determined upon may be mentioned the adoption of electrical propulsion for the Mersey Railway in Liverpool, and for the Metropolitan and District Railways in London, both to a large extent with the aid of American capital. For the latter, two systems were considered—the Ganz polyphase and the ordinary direct current. The question which should be selected was referred to the Board of Trade for decision, and as soon as that step was taken the matter was practically settled, for few could doubt but that so eminently conservative a body would choose a system which has been well tried in various parts of the world, in preference to one which has scarcely passed the experimental stage, and which, moreover, involves the employment of electricity at a much higher pressure than it is used to. In another case also the Board was made master of the situation, for Parliament, while passing the Bill for the Behr Monorail high-speed line between Liverpool and Manchester, practically delegated the power to authorize the construction of the line to that body, which must approve of the engineering details before work can be begun, and may require the promoters to carry out any preliminary experiments it thinks necessary. From the point of view of public safety there are doubtless advantages in this policy of entrusting everything to the Board of Trade, but its practical effect will probably be that British engineers will be debarred from taking the lead in any new electrical development which conceivably involves risk to human life. In connection with high-speed lines, mention must be made of the experiments carried out in Germany on the Berlin-Zossen military line, where, by the aid of electricity at a high voltage, a speed of about 100 miles an hour was obtained, not, it would appear, without some damage to the permanent way.
That wide field of inquiry which lies in the borderland between physics and chemistry is attracting an ever-increasing number of workers. Though no discovery of outstanding importance was made, the Cambridge school can point to a year of solid work on the phenomena of ionization and the existence of bodies many times smaller than molecules, and, in spite of the protests of some chemists, the ionic dissociation hypothesis continues to find increasing favor among the great body of physicists. In France progress was made in the investigation of the radio-active bodies by M. and Mme. Curie, Becquerel, and others; the first-named inquirers made the observation that the rays emitted by radium exercise a burning and eroding effect on the skin. In Germany, Bredig and Ikeda continued their remarkable experiments with 'inorganic ferments,' in particular following out the analogy between the catalytic action of colloidal platinum and that of organic ferments in regard to the action of poisons. They find that the rate of decomposition of hydrogen peroxide in presence of colloidal platinum is inliuenced to an extraordinary degree by substances like prussic acid, hydrogen sulphide, and mercuric chloride, even in minute quantities. Thus the catalytic effect of a platinum solution is halved by prussic acid, even when the concentration of the latter is only 0.0014 milligram per liter; the effect of this substance is, however, only temporary, and the solution gradually recovers in course of time. A large number of substances exert this poisoning action to a greater or less extent, but there are some which intensify the catalytic action of the colloidal platinum, among them being formic acid and dilute nitric acid. Experiments have also been tried with a colloidal solution of gold obtained in a manner similar to that employed in the case of platinum, by passing an electric current between gold wires in a dilute solution of sodium hydroxide. This gold solution, which is bluish-violet in color and contains one gram atom of gold in 1,360 liters, on the whole resembles colloidal platinum in its action, but it is remarkable that the same agents are not poisonous to both. Thus mercuric chloride, one of the strongest poisons for colloidal platinum, exerts an opposite influence on the catalyzing power of colloidal gold in alkaline solution.
Professor Gamgee's investigations into the magnetic qualities of the blood again touch physics on the one hand and physiology on the other. Starting from Faraday's observation that blood is a diamagnetic fluid in spite of the iron contained in its coloring matters, he has found that, while oxy-hæmoglobin is powerfully diamagnetic, the hæmatin and hæmin which may be obtained from it by the action of certain acids are strongly magnetic. He is extending his inquiries to the products obtained by the electrolysis of oxy-hæmoglobin. Mr. H. Swithinbank has been carrying out an elaborate investigation into the effects produced on tubercle bacillus by exposure to the cold of liquid air. He finds that prolonged exposure to that temperature, and even actual soaking in liquid air, has little or no effect on the vitality of the bacillus, though its virulence is to some extent modified. Length of exposure, indeed, does not seem to be an important factor, but what does produce a decided destructive effect on the vitality and virulence is exposure to alternations of temperature, as when the bacillus is frozen in liquid air, allowed to warm up to normal temperature, cooled again, and so on. The most striking incident at the Tuberculosis Congress held in London in July was the pronouncement by Professor Koch that bovine and human tuberculosis are distinct diseases, and that consumption is not transmissible from cattle to human beings. His views by no means commanded universal assent, and it was generally felt that more evidence was required before they could be accepted, and especially before any relaxation could be seriously contemplated in the sanitary regulations which have been framed on the assumption that the disease is so transmissible. During the proceedings of the Congress great stress was laid on the value of the open-air treatment of consumption, and as a result a strong impetus was given to the movement for establishing sanatoria where it can be carried out. One important semi-public institution of the kind was brought into use near Wokingham in the course of the year, and the erection of several others in various parts of the country has been determined upon. A sum of £200,000 placed at the disposal of the King by Sir Ernest Cassel has also been devoted by His Majesty to the erection of one of these sanatoria. Another mode of treating consumption, which did not receive nearly so much attention at the Congress, has been tried by Dr. Maguire, of the Brompton Consumption Hospital, with very promising results. This consists of the intravenous injection of formalin in carefully-graduated strengths and amounts. The effect, even in some very advanced cases, has been a rapid lowering of the temperature, and even after the immediate action of the injection has passed off the patient experiences relief from the malaise which is so distressing a consequence of high temperature. The drug appears to possess in particular a controlling influence on streptococcic and staphylococcic infection, and it seems probable that its use may be extended to the treatment of other diseases.
Increased light is being thrown on mosquitoes as agents in the propagation of disease. Not only has more detailed information been gained as to the part they play in the causation of malaria, preventive measures based on that information being put in operation with a certain amount of success, but evidence has been brought forward which indicates that the spread of yellow fever also is due to them. That disease, at least, has developed in persons who have been bitten by mosquitoes, while others protected from mosquitoes have escaped, even though they courted infection, according to older ideas, by wearing clothes and sleeping in bedding which had been used by yellow fever patients. In Glasgow there was an outbreak of smallpox in the early part of the year, and plague appeared in one of the large hotels; but, owing to the vigorous measures adopted, neither disease succeeded in gaining any stronghold. In London, too, smallpox is prevalent to a greater extent than it has been for a considerable period, though there can scarcely be said to be an epidemic in the sense in which that term was used twenty or thirty years ago.
In natural history the most interesting discovery was that of a new mammal in the Congo Hinterland. Sir Harry Johnston obtained from the Semliki Forest a complete skin and two skulls, and a reconstruction of the animal may now be seen in the Natural History Museum at South Kensington. At first it was thought to be of a zebra-like character, on the evidence of certain stripes on its skin, but further investigation dispelled that notion, and Professor Ray Lankester has diagnosed it as a giraffine animal. It has been named Okapi Johnstoni.
The men of science who died during the year include three who took high rank among physicists—Professor Tait, of Edinburgh, Professor Fitzgerald, of Dublin and Professor Rowland, of Baltimore. The first-named had reached the age of three score and ten, but the other two were both comparatively young men from whom much good work, in addition to what they had already achieved, might confidently have been expected had they lived. Both education and science were the poorer by the death of Principal Viriamu Jones, of University College, Cardiff, in succession to whom another physicist has been appointed in the person of Mr. E. H. Griffiths. On the other hand, two veterans of science—Virchow in Germany and Berthelot in France—celebrated the completion of fifty years of scientific work.
- From the London Times.